Seat valve having rotating closure member for variable pressure control

ABSTRACT

A seat valve for controlling pneumatic or hydraulic pressure between at least two pressure fluid channels ( 8, 8 ′) includes a valve closure member ( 5 ) connected to a magnetic armature ( 4 ), a spring for the basic positioning of the valve closure member ( 5 ) in relation to a valve seat ( 7 ) in the valve housing ( 6 ), a magnetic core and a valve coil for the translatory movement of the magnetic armature ( 4 ). A control channel ( 1 ), a tappet ( 2 ), a sleeve ( 2 ′), a rotating field winding ( 3 ), and an opening  3 ′) are provided to produce a rotary movement of the magnetic armature ( 4 ) and to transmit the rotary movement to the valve closure member ( 5 ) for the variable control of a pressure fluid passage.

BACKGROUND OF THE INVENTION

The present invention relates to a seat valve for the control ofpneumatic or hydraulic pressure between at least two pressure fluidchannels.

German patent application No. 40 30 571 discloses an electromagneticseat valve, closed in its de-energized condition, for the control ofhydraulic pressure, which includes a magnetic armature to which a valveclosure member is attached, and a spring that urges a valve closuremember against a valve seat by a defined preload. The valve seat ismounted in the valve housing. Further, a magnetic core is accommodatedin a thin-walled valve sleeve and a valve coil is secured to the valvesleeve. The winding of the valve coil is configured so that the magneticarmature performs exclusively a translatory movement so that the valveclosure member is either opened or closed stroke-responsively as afunction of the electromagnetic energization of the valve coil. Thisproduces a binary switching behavior with relatively quick strokemovements. However, a variable adjustment of the rate of fluid flow isnot permitted thereby.

An object of the present invention is to improve a seat valve of thetype mentioned hereinabove by simple and functionally reliable means tosuch effect that in addition to the actual translatory movement of thevalve closure member the rate of fluid flow can be adjusted variablywith minimum possible electric energy demand.

SUMMARY OF THE INVENTION

According to the present invention, this object is achieved for a seatvalve of the generic type by producing a rotary movement of the magneticarmature and transmitting the rotary movement to the valve closuremember for a variable control of a pressure fluid passage.

Further features, advantages and possible applications of the presentinvention can be seen in the following in the description of twoembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 is an expedient construction of the basic elements of the objectof the present invention.

FIG. 2 is a top view of a rotating field winding and a magnetic armaturefor use in the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

The FIG. 1 embodiment shows an enlarged partial view of a normallyclosed seat valve for the control of pneumatic or hydraulic pressure.The seat valve has a substantially spherical valve closure member 5which, in the initial position shown in the drawing, moves into sealingabutment on a generally plate-shaped valve seat 7. Succeeding the valveclosure member 5 is a tapering transition area to a tappet 2, and thetappet 2 is sealed within a sleeve 2′ so that leakage is prevented. Thewall of sleeve 2′ has an opening 3′ which (as shown) is covered by thestem of tappet 2 in a pressure-fluid tight manner. On the stem portionof the tappet 2 remote from the opening 3′, there is a control channel1, acting as a control groove, which can be moved to overlap opening 3′by rotation of the tappet 2. Opening 3′ is connected to a pressure fluidchannel 8′ by way of an annular chamber in a valve housing 6. A pressurefluid channel 8 connected downstream of the valve closure member 5 inthe drawing is isolated from the pressure fluid channel 8′ due to theclosed position of the valve closure member 5 and due to the stemportion of tappet 2 which closes the opening 3′. FIG. 1 relatesexclusively to the basic construction elements in the area of the valveclosure member 5, without discussing possible details of the design.Thus, FIG. 1 can be considered as a block diagram of the presentinvention. Although the valve portion adjacent to tappet 2 is not shown,basically, one has to expect a seat valve design as disclosed in Germanpatent application No. 40 30 571, wherein adjoining the tappet 2 is amagnetic armature 4 in a closed valve housing 6 which is encompassed bya valve coil that generates the magnetic armature stroke.

Further details of the design of the magnetic armature 4 and the coilwinding according to the present invention can be taken from the FIG. 2embodiment hereinbelow. FIG. 2 shows a top view of the magnetic armature4 which generally has a star-like configuration in its cross-sectionalprofile. Armature 4 is movable both translatorily and rotatorily insidethe valve housing 6. The sleeve-shaped valve housing 6 which is shadedin the area of the magnetic armature 4 accommodates on its outside walla rotating field winding 3 which, depending upon the electricenergization and, thus, variation of the rotating field, rotates themagnetic armature 4 by a defined angle. This also causes the controlgroove (control channel 1) on the tappet 2 to more or less move tooverlap with the opening 3′ so that the pressure fluid passage betweenthe two pressure fluid channels 8, 8′ can be varied when the valveclosure member 5 is open. The mode of operation may be identical withthe operating principle of a reluctance motor, wherein upon generationof a rotating field in the rotating field winding 3 the magneticarmature 4 and, thus, the tappet 2 rotates with selectively adjustablerotating speeds. This permits varying at will the pressure fluid flowrate and, thus, the time interval during which the opening 3′ and thechannel 1 overlap each other. A reversal in the direction of rotation ofthe magnetic armature 4 is equally possible in a corresponding actuatingprocess so that the armature may temporarily turn the tappet 2 to andfro in order to alternately overlap the opening 3′. The valve coil whichis required for the stroke movement of the magnetic armature 4 can bestructurally combined with the rotating field winding 3. The valve coilthen includes two independently actuatable winding parts, one part beingintended for closing and opening the valve, and the other partdetermining the rotating angle orientation of the magnetic armature 4.

The advantage of the object of the present invention is that both theeffect of the rotating field and the translation of the magneticarmature are possible separately from each other as well as insuperposition. This implies that the tappet 2 can rotate in the closedand the open condition, in order to pre-adjust a large or a smallcontrolling cross-section between the opening 3′ and the channel 1 asneeded, or to vary the controlling cross-section alternatively duringthe stroke of the magnetic armature. The flow rate is thus controllableor adjustable in analog operation. Pressure variations of the fluid donot cause impairment of the necessary adjustment forces at the magneticarmature. The object of the present invention ensures an energeticallyfavorable opening and closing of the valve with a correspondingly smallair slot of the magnetic armature.

LIST OF REFERENCE NUMERALS

1 control channel

2 tappet

2′ sleeve

3 rotating field winding

3′ opening

4 magnetic armature

5 valve closure member

6 valve housing

7 valve seat

8,8′ pressure fluid channels

What is claimed is:
 1. A seat valve for controlling the pressure betweenat least two pressure fluid channels including a valve housing having avalve seat, a valve closure member connected to a magnetic armature, aspring for basic positioning of the valve closure member in relation tothe valve seat in the valve housing, a magnetic core and a valve coilfor translatory movement of the magnetic armature so as to move theclosure member into and out of engagement with the valve seat, a tappetwith a longitudinal control channel that connects the magnetic armatureto the valve closure member, the valve closure member being guided in asleeve which seals in-between the valve seat and the valve housing andincludes an opening that radially penetrates the sleeve, thelongitudinal control channel overlapping, at least in sections, theradial opening depending on the angular rotary position of the tappet,the magnetic core having a winding configured to generate a rotatingmagnetic field that embraces the magnetic armature for producing arotary movement of the magnetic armature, the tappet transmitting therotary movement to the valve closure member for variable control of apressure fluid passage wherein the magnetic armature comprises aplurality of first poles, the magnetic core comprising a plurality ofsecond poles.
 2. The seat valve of claim 1 wherein the variable controloccurs as a function of said overlapping with respect to time.
 3. Theseat valve of claim 1 wherein the rotary movement is produced accordingto a reluctance effect.
 4. The seat valve of claim 3 wherein thevariable control of the pressure fluid passage is determined as afunction of an angular speed of rotation of the magnetic armature.